Does injection into the dominant or nondominant eye affect the outcome of botulinum toxin injection for recurrent strabismus?

Abstract

Botulinum toxin injections may be used for patients with recurrent strabismus. We hypothesized that injection into the dominant eye would be more effective than injection into the nondominant eye, because there would be a greater stimulus to restore binocularity by inducing temporary misalignment of the preferred eye. Retrospective review of 46 patients with moderate angle recurrent esotropia following previous extraocular muscle surgery. Patients with deprivation amblyopia or developmental delay were excluded. Injection into the dominant eye was usually recommended, but the injection was performed in the nondominant eye if the parents preferred. The pre- and postoperative records were analyzed. Forty-six patients with recurrent esotropia of 14Δ -25Δ were treated with Botulinum toxin. The injection was performed in the nondominant eye in 21 patients (average deviation 19.6Δ; average age 4.9 years), and in the dominant eye in 25 patients (average deviation, 18.9Δ; average age, 5.6 years). Follow-up was more than one year in all patients (average, 4.4 years)Treatment was successful in 13/21 (61%) of patients in the nondominant group and 14/25 (56%) of patients in the dominant group. There was no significant difference in the outcome of botulinum toxin injection for recurrent esotropia between patients who received injections in the dominant or nondominant eye. The efficacy of botulinum toxin for recurrent strabismus is not affected by ocular dominance. Therefore, other factors may be considered when deciding which muscle to inject.